Compressor inspection port



Dec. 20, 1960 w. A. LEDWITH ET AL 2,965,286

COMPRESSOR INSPECTION PORT Filed Dec. 2l, 1956 /NVENTORS WALTER LEDW/ TH JHN C. CARR BV @ZAM COM A TTORNEV Cor/rrnnsson rNsrncrroN Ponr Walter A. Ledwith, Giastonhury, and `lohn C. (Iarr, Unionville, tllonn.,J assignors to United Aircraft `Cor-- poration, East Hartford, Conn., a corporation of Delaware Filed Dec. 21, 1956, Ser. No. 629,999

8 Claims. (Cl. 23d-1313) This invention relates to inspection ports for use in an axial dow compressor.

In many of these devices, inspection of the vanes or blades is desirable especially after a period of operation t determine whether the blades have been damaged. Such inspection has required a substantial disassembly of the compressor in order to permit access to the rotor for inspection of the blades thereon. One feature of the invention is the provision for inspection ports in the casing to permit the insertion of tools by which the blade may be inspected.

if the inspection tools are inserted in line with the blades, turning of the rotor for inspecting all of the blades in each row may cause injury to the inspecting tools or the blades. Another feature of the invention is the provision of inspection holes which are located out of alignment with the rows of moving blades. Another feature is the location of the inspection port or ports in line with the stationary vanes with the outer end of one of the vanes closing the inspection port.

One feature of the invention is the provision of inspection ports in the outer casing and in the shroud ring with a slug closing the port at the outer casing and providing access to the closure in the shroud.

Other features and advantages will be apparent from the specification and claims, and from the accompanying drawings which illustrate an embodiment of the invention.

Fig. l is a fragmentary longitudinal sectional view through an axial flow compressor incorporating the invention.

Fig. 2 is an enlarged section of one of the details of Fig. 1.

Fig. 3 is a View similar to Fig. 2 showing another of the inspection ports.

Fig. 4 is a sectional View substantially along the line 4 4 of Fig. l.

The invention is shown in a multi-stage axial ow compressor having an outer casing made up of two annular sleeves 2 and 4 bolted together at adjacent ends as by bolts 6. The sleeve i has an outwardly extending flange 8 at its upstream end through which the bolts 6 extend and an inwardly projecting flange ld at its downstream end which engages with the series of shroud elements l2 and spacers 14 which support the rows of radially inwardly extending vanes i6. The spacers may be integral with the shroud elements lil.

The sleeve 2 has a flange l at its downstream end which receives the bolts 6 and may have a suitable attaching means such as a flange 2t), at its upstream end to which a bearing supporting housing for the rotor may be secured. Within the sleeve 2 and spaced therefrom is a concentric sleeve 22 forming the inner wall of the casing. The upstream end of the sleeve 22 has a shoulder 24 engaging with the end of the stack of spacers 14 and shrouds 12 and the downstream end of the sleeve 22 has a projecting flange 26 engaged by a portion of the flange 1S and thereby held in position by the bolts 6.

The rows of vanes 16 alternate with rows of blades 28 on the rotor 39 and the invention is intended to permit inspection of these several rows of blades 28 without the need for substantial disassembly of the compressor. The stack of shrouds 12 and spacers 14 may be of any suitable construction as described, for example, in the Hasbrouck and Shinn Patent'No. 2,749,0126. For the purposes of this invention, the outer ends of each row of vanes 16 is supported by a pair of rings 32 which are spaced apart, as shown, and which provide a firm support for the vanes. The inner ends of the vanes in each row engage with an inner shroud ring 34, each of the vanes, for example, having an inwardly extending tang 36 fitting in a similarly shaped opening 38 in the inner shroud.

It will be understood that other supporting means for the vanes may be used equally well and that the particular arrangement of the outer shroud made up of spaced rings 32 is shown merely by way of example.

In order to provide for inspection of the blade, alternate rows of vanes 16 have one vane in each of the alternate rows which can be removed radially to provide for the insertion of an inspection tool therein. For example, as shown in Fig. 2, the removal of the vane 40 will permit the insertion of an inspection tool which can inspect the blades of rows 28a and 281;.

In order that the vanes 40 may be Withdrawn, the casing sleeve t has a ring 42 fastened therein which has an opening receiving a plug 44 preferably threaded into the ring. The inner end of the plug engages the outer end of the vane 40, and holds it in the position shown during normal operation. The shroud ring 12a which supports the outer end of the row of vanes in which the vane 4l) is located, has an opening 46 therein which receives the enlarged outer end 4S of the vane eti, the inner end of the vane tting in the appropriate opening 38 in the inner shroud. It will be understood that the vane end 48 is a slidable tit in opening 46 in order to permit withdrawal of vane 40.

The opening 46 extends nearly to the adjacent vane on each side of vane itl to provide as large an opening as possible for the insertion of the inspecting tool. A threaded opening Sti in the outer end of vane 40 receives a threaded tool by which the vane may be withdrawn radially from the position shown. Plug 44 may have a hexagonal recess 52 in the outer end to receive a suitable wrench.

For the portion of the compressor having the inner casing sleeve 22, as shown in Fig. 3 the plug 54 is mounted in its supporting ring '56 which is secured in the outer sleeve 2. The plug carries a disc S8 in a position to align with the inner sleeve and slidable radially of the plug to a limited extent. The disc is held in position between a washer 60 and a surface 6l on the plug. A clearance 60 radially between the washer and the plug permits this radial sliding movement such that a slight misalignment of the rings 62 and '56 may be accommodated. This disc 58 fits in a ring 62 in the inner casing sleeve 22, as shown. A snap ring 63 holds washer 6l) in position. The vane 64 is similar to the vane 4d, and has the enlarged outer end 66 tting in the opening 68 in the outer shroud. The vane 64 also has a threaded opening 7d in the outer end to receive the tool by which the vane is Withdrawn. The disc '58 and cooperating ring 62 provide for relative expansion both axially and circumferentially between sleeves 2 and 22, as will be apparent. As can be seen in the drawing, the disc 58 is smaller in diameter than the plug receiving opening in ring 56 to permit the entire plug to be withdrawn as a unit.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as dened by the following claims.

We claim:

l. In a compressor construction, a stator construction including a casing having a plurality of rows of stator vanes therein and a rotor having rows of blades alternating with said rows of vanes, said vanes being xed in and extending radially inwardly from said casing, one vane of at least one row of said vanes having an enlarged outer end and a removable radially extending plug in said casing engaging with the outer end of said one Vane only for holding said one vane only radially in position, said one vane being radially removable from the casing to permit inspection of the rows of blades adjacent thereto, said one vane having attachment means in its outer end to provide for withdrawal of said vane.

2. In a compressor construction, a stator construction including a casing, at least one shroud ring within and supported by the casing, a plurality of rows of vanes supported by said shroud ring and extending radially inward therefrom, one vane of at least one row of said vanes being a radially slidable t within said shroud, said casing having an opening outwardly of and in substantially radial alignment with said radially slidable vane, and a removable plug in said opening and engaging with said Vane to hold said vane radially in position, said opening being large enough for withdrawal of the vane therethrough.

3. In a compressor construction, a stator construction including a casing, at least one shroud ring within and supported by the casing, a plurality of rows of vanes supported by said shroud ring and extending radially inward therefrom, one vane of at least one row of vanes being a radially slidable t within said shroud, said casing having an opening in substantially radial alignment with said one vane, and a removable plug in said opening and engaging the outer end of the vane to hold said vane radially in position, said vane having attachment means in its outer end to provide for radial Withdrawal of said vane through said opening when said plug is removed, said opening being larger than said one vane to permit such radial withdrawal.

4. In a compressor construction, a stator construction including a casing, at least one shroud ring within and supported by the casing, a plurality of rows of vanes supported by said shroud ring and extending radially inward therefrom, one vane of at least one row of vanes being a radially slidable tit within said shroud, said vane having an enlarged outer end thereon, and said shroud having an opening in which said outer end is radially slidable, said casing having an opening in substantially radial alignment with said one vane, and a removable plug in said opening and engaging the outer end of the vane to hold said vane radially in position, said vane having attachment means in its outer end to provide for radial withdrawal of said vane through said opening when said plug is removed, said opening being larger than the enlarged outer end on the vane.

5. In a compressor construction, a stator construction including a casing, at least one shroud ring within and supported by the casing, said casing including a portion consisting of inner and outer annular elements the inner of which is spaced radially inward from the outer, a plurality of rows of vanes extending inwardly from the shroud ring, one vane of at least one row being radially slidable within said shroud ring, said inner and outer casing elements having openings therein in radial alignment with each other and with said one vane, and a plug threaded in the opening in one of said elements and engaging the outer end of said one vane, said plug having means thereon tting within the opening in the other element.

6. In a compressor construction, a stator construction including a casing, at least one shroud ring within and supported by the casing, the latter including a portion consisting of inner and outer annular elements the inner of which is spaced radially inward from the outer, a plurality of rows of vanes extending inwardly from the shroud ring, one vane of at least one row being radially slidable within said shroud, said inner and outer elements having openings therein in radial alignment with said one vane, and a plug threaded in one of said elements and having a radially movable collar thereon fitting in said other opening, said plug engaging the outer end of said one vane.

7. In a compressor construction, a stator construction including a casing, at least one shroud ring within and supported by the casing, a plurality of rows of vanes supported by said shroud ring and extending radially inward therefrom, one vane of at least one row of vanes being a radially slidable iit within said shroud, said casing having an opening in substantially radial alignment with said one vane, said opening being larger than said one vane for radial insertion of said vane through said opening, and a radially extending removable threaded plug in said opening, the inner end of said plug engaging the outer end of said one vane to hold said vane radially in position.

8. A compressor construction as in claim 7 in which an inner sleeve is located between the casing and the shroud in concentric relation thereto, the inner sleeve has an opening in alignment with the opening in the casing and also larger than said one Vane, the plug having a disc thereon to iit in the opening in the sleeve when the plug is in position in the casing.

References Cited in the iile of this patent UNITED STATES PATENTS 2,640,319 Wislicenus June 2, 1953 FOREIGN PATENTS 572,859 Great Britain Oct. 26, 1945 599,391 Great Britain Mar. 1l, 1948 891,422 France Dec. 1l, 1943 

